Heat exchange structure for air heating furnaces



Sept. 11, 1956 Filed Sept. 30, 1952 F. DRUSEIKIS HEAT EXCHANGE STRUCTURE FOR AIR HEATING FURNACES 3 Sheets-Sheet 1 g A? u 37 r. w

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ATTORNEYS F. DRUSEIKIS Sept. 11, 1956 HEAT EXCHANGE STRUCTURE FOR AIR HEATING FURNACES 3 Sheets-Sheet 2 Filed Sept. 50, 1952 w J t T Mm M W M m M w P y 1i i m \Illl. llll 2 L U JT IK Y n. J M

11 f l l 1 k 1 3511 WW1 F. DRUSEIKIS Sept. 11, 1956 HEAT EXCHANGE STRUCTURE FOR AIR HEATING FURNACES Filed Sept. '50, 1952 5 Sheets-Sheet 3 ll|||||||l 1'' If] M Mm United States Patent HEAT EXCHANGE STRUCTURE FOR AIR HEATING FURNACES Frederick Druseikis, Churchville, N. Y., assignor to General Motors Corporation, Detroit, Mich, a corporation of Delaware Application September 30, 1952, Serial No. 312,343

' 3 Claims. Cl. 257-256) The present invention pertains to heat exchange structure for air heating furnacesfor conditioning the air in enclosures, and has particular reference to warm air heating systems for this purpose.

In warm air-heating systems, the thermal efliciency of the unit is to a large degree dependent upon the. heat transfer area exposed to the circulating air. Generally the greater surface area in intimate contact with both the hot flue gases and the circulating air whereby the circulating air is heated. by conduction and convection, the more eflicient is the unit. However, space requirements limit the amount of, area available for heat exchange surfaces and, accordingly, some sacrifices in the overall thermal efliciency of the unit are necessary. Hollow radiator sections, which the hot flue gases traverse in flowing from the combustion chamber to the. stack, have long been employed in an effort to increase the thermal efl'iciency of warm air heating units. However, prior structures have not been universally adopted in the construction of. small, compact domestic units due to the fact that the radiator sections were dimensionally incompatible with the space available in these units. Accordingly, among my objects are the provision of a novel heat transfer or radiator section and a furnace construction adapted to use the aforementioned radiator sections.

The aforementioned and other objects are accomplished in the present invention by designing the radiator sections as individual assemblies whereby the number of sections associated with any particular furnace construction is determined by the available space. Specifically, the radiator sections are designed for attachment to each other, as well as for attachment to the combustion chamber of a furnace. Preferably, the combustion chamber has an opening therein, which opening is adapted to be closed by the radiator section assembly. The heat exchange surfaces of the individual radiator sections comprising the radiator assembly are spaced from each other to facilitate the transfer of heat to the circulating air. Each radiator section has two openings, one adapted for communication with the combustion chamber and the other adapted for communication with a' collector assembly for routing the flue gases to a stack. In addition, each radiator section includes a replaceable internal baffle structure for directing the'hot flue gases in acircuitous path from the inlet to the outlet thereof wherebythe efiicacy of heat exchange will be enhanced.

Further objects and advantages of thepresent invention will beapparent from the following description,.reference being had to the accompanying drawings wherein a preferred. embodiment of the present invention is clearly shown.

In the drawings:

Fig. 1 is a view in elevation with the exterior side panel removed of a furnace constructed according to the present invention.

Fig. 2 is an enlarged fragmentary view in elevation of the novel radiator and collector assembly.

2,762,612 Patentedsept. 11, 1956 Fig. 3. is a: view partly in section and partly in eleva tion taken in the direction of arrow 3 in Fig. 2.

Fig. 4 is a view in elevation of one of the parts comprisingv a radiator section.

Fig. 5 is a view taken in the direction of arrow Sin Fig. 4.

Fig. 6 is a view taken in the direction of arrow 6v in Fig-2.

With particularreference to Fig. l of the drawings, the invention is herein disclosed in conjunction with a furnace or heating unit having. a rectangular casing 10 of sheet metal or any other suitable material. The casing 10 has a cold air inlet 11 adjacent the bottom thereof, a warm air outlet 12 at the top thereof and a stack outlet 13 in one of the sidewalls adjacent the top of the casing.

As exemplified, the furnace includes a combustion chamber 14' mounted within the casing 10 within which a combustible mixture is burned. By way of illustration, an oil burner unit 15'is employed to'supply the combustible mixture to the combustion chamber 14. A blower 16 is utilized to force the circulating air from the inlet 11 to the outlet 12 ofthe casing 10.

The combustion chamber 14 is generally of dome-shape configuration, the upper end 17 of which is open. Attached'v to' the open end 17 of the combustion chamber is a radiator, or heat transfer section assembly, 18 comprising a plurality of heat transfer sections 19 disposed in spaced side by side relationship within the casing or housing 10. The detailed construction of the radiator sections 19 willhereinafter be described. but for the present, it: will sufllce to say that each section has an inlet openingcommunicating with the open end 17 of the combustion chamber and an outlet opening communicating with a collector assembly 26 whereby the hot gaseous products of combustion traverse the radiator sections in a circuitous route from the combustion chamber 14 to the stack outlet 13. The radiator assembly constitutes part of the heat exchange surface presented to the circulating air in its flow from the inlet to the outlet of the casing 10, which air is forced between the several radiator sections by the blower 16.

With particular reference to Figs. 3 to 5 of the drawings, each radiator section 19 is formed by a pair of sheet metal stampings 21 and 22. The metal stampings 21 and 22 of. the radiator sections 19 are outwardly dished to provide spaced sidewalls defining an inner space for the flow of hot flue gases. As is seen in Figs. 4v and 5, the stamping 21. has lip portions 23, 24, and 25 on three of its peripheral edges, which lip portions are adapted to be clamped over complementary upstanding portions of the metal section 22, as is shown in Fig. 3. Thereafter, the assembly of the left and right hand stampings are rigidly connected. by any suitable means such as spot welds 26, as. isv shown in Fig, 2. Portions of the peripheral edge opposite the lip 23 are curved outwardlyand flanged at 27 and inwardly at 28, respectively, as is shown in Fig. 5, whereby when the complementary sections are assembled to form a radiator .unit 19, the edge 30 of the portion 28 may be spot and edge welded, or otherwise suitably connected to insure a. gas tight joint, to the corresponding portion. of. the stamping 22, such as is shown at 29 in Fig. 6.

The edge 31 of the portion 27 is likewise welded to the complementary edge of a similar portion 27 provided by an adjacent radiator section 19 when the radiator sec.- tions. are assembled to enclose the opening of acombustion chamber, as is shown in Fig, 3. An angle member 32 is rigidly attached to the inner surface of each of the stampings 21 and 22 comprising a radiator section 19 for supporting a baffle assembly 33 whereby the hot flue gases are forced to traverse a circuitous path from the combustion chamber to the stack.

Each radiator section 19 has an inlet opening at 34 and an open end 35 constituting an outlet Opening. The combustion chamber 14 having an open end 17 is constructed to support a radiator assembly, or unitary heat exchanger, comprising a number of spaced heat transfer sections 19, which number is determined by the size or B. t. u. capacity of the furnace. In the particular construction shown in the drawings, the furnace is designed to employ four spaced radiator sections formed as an integral unit by welding the contiguously disposed edges of the portions 27 forming seams 34. Moreover, the interconnected portions 27 of the radiator sections form a chamber interconnecting the adjacent radiator sections and communicating with the inlet openings 34 thereof. The oppositely extending portions 27 and 27 of the end radiator sections are welded to parallel sidewalls adjacent the opening 17 of the combustion chamber 14. The front and back walls of the combustion chamber are formed with a plurality of projections 35a and 36, respectively, for locating the radiator section assembly prior to its being Welded to the combustion chamber.

The spaced open ends 35 of each section constituting part of the radiator assembly, or unitary heat exchanger 18 are received by openings in a member 37 constituting a part of a collector assembly 38. The member 37 is provided with flanged portions 39 and 40 adjacent the periphery of each of the openings therein, which flanged portions are rigidly attached to each of the radiator sections by any suitable means, such as welds. Positioned over the open ends 35 of the radiator sections 19 is a plate member 41 having a plurality of openings 42 equal in number to the number of radiator sections'19 in the assembly. The plate 41 is suitably retained in position by means of a plurality of screw devices, such as those shown at 43, which interconnect the member 37 and the plate 41. The openings 42 in the plate 41 are of sufiicient size to permit the insertion of baffle assemblies 33 with each of the radiator sections 19, the baffie assemblies being supported upon the angle members 32. The baflle assemblies 33 may be attached to the plate 41 by means of a screw device 44, such as is shown in Fig. 2. Each bafile assembly 33, as shown, includes a horizontal plate 45 having a downwardly extending portion 46 at one end thereof and an upwardly directed portion 47 adjacent the other end thereof. By reason of their attachment to the plate 41, the bafiie assemblies 33 can be removed from the radiator sections 19 to facilitate cleaning thereof, should the necessity arise. The collector assembly 38 is completed by a member 48 removably connected to the member 37 by any suitable means, such as screw threaded devices 49. The member 48 is provided with a circular opening 50 to which a tubular member 51 is connected for directing the flue gases to a stack, not shown.

In operation the oil burning unit 15 discharges, the ignited combustible mixture into the combustion chamber 14 from whence the hot flue gases follow the path indicated by the arrows in Fig. 2 from the open end 17 of the combustion chamber to the stack receiving member 51. envelops the combustion chamber 14 and flows in the direction of arrows in Fig. 1 between the spaced radiator sections 19 in the radiator assembly 18 and through the outlet 12 of the casing. One of the openings 42 in the plate 41 is larger than the remaining ones and is adapted to provide space for the insertion of a stack thermostat device 52, Fig. 1, used in conjunction with the control circuit for the oil burning unit 15. The cross sectional area of this opening is such that the area available for the flow of flue gases is substantially the same as those within which a stack switch thermostat 52 is not disposed.

From the foregoing it is readily apparent that the pres- The air circulated by the fan 16 within a casing 10 cut invention provides a radiator section assembly, which can be readily adapted to any size of heating unit by merely adding additional sections to completely enclose the openingin the combustion chamber. Moreover, the provision of a replaceable baffle assembly within each of the radiator sections is an important aspect of the present invention in that it facilitates cleaning of the radiator sections, should the necessity arise in use.

While the embodiment ofthe present invention as herein disclosed, constitutes a preferred form, it is to be understood that other forms might be adopted.

What is claimed is as follows:

1. A heat transfer section adapted for connection with other like sections to form a unitary heat exchanger comprising, a pair of sheet metal members having at least portions of three peripheral edges clampingly engaged and rigidly united, said members also having outwardly directed edge portions arranged for connection to like portions of adjacent sections to form an interconnecting chamber between adjacent sections, the intermediate sidewall portions of said members being outwardly dished to define an inner space for the flow of a heated fluid which communicates with said chamber, two peripheral surfaces located at substantially right angles to each other of said section having openings constituting an inlet communicating with saidchamber and an outlet communicating with said inner space, and means carried by the sidewall portions of said members for removably supporting a bafile assembly within said inner space so as to provide a circuitous path for the flow of hot fluid from the inlet to the outlet thereof.

2. The combination set forth in claim 1 wherein the means attached to the sidewall portions of said members for removably supporting a baflie assembly comprises a pair of brackets having inwardly directed portions which constitute a supporting surface for said baffle assembly.

3. A heat exchanger for a warm air furnace comprising, a plurality of heat transfer sections, each heat transfer section comprising a pair of members having outwardly dished, substantially flat walls and laterally ex tending edge portions on at least parts of three peripheral edges constructed and arranged to be clampingly engaged and thereafter rigidly united so as to define an inner space for the flowof hot flue gases, each section having a pair of peripheral openings therein which communicate with said inner space for the entrance thereinto and exit therefrom ofhot flue gases, each member of each heat transfer section also having a pair of lateral edge portions extending in opposite directions adjacent said entrance opening, and means uniting the last mentioned edge portions of adjacent sections to form an interconnecting chamber between the adjacent sections of the heat exchanger, said interconnecting chamber communicating vwith the inner space of each heat transfer section through the entrance opening therein.

References Cited in the file of this patent UNITED STATES PATENTS 

